Officer Ryan Linville cruised through a city parking lot Monday, looking for hot plates.

Picking up cooking implements wasn’t on his to-do list, though. He was operating the city’s new automated license plate reader, which captures photos of vehicle license plates and checks them against a list of wanted plates to help the police fight a variety of crimes.

As Linville drives, his in-car computer emits a beep whenever the computer reads a license plate. A photo of each captured plate pops up on his in-car computer screen.

Suddenly, the alarm on the system starts going off. Linville stops and checks the photo on his screen. The system is alerting on a city parks and recreation vehicle parked at the end of a row of cars.

The car isn’t stolen, though. Moments before driving by, Linville had added its plate to the hot list to demonstrate how the system works.

“It’s an excellent tool,” Linville said. “It’s already recovered one stolen tag. Hopefully, it will be able to be used for a crime in progress or a missing child.”

The city purchased the system with a $17,000 grant from the State Homeland Security Program. It has been in operation for about a month.

The system includes two infrared cameras mounted on either side of the vehicle’s trunk. Wires run to a power source and ethernet connection inside the trunk, and software is installed on the in-car computers.

Two cars downtown and two in North Suffolk are equipped with the new system, Linville said. A total of eight officers went through training to operate the system.

At the beginning of each shift, an updated “hot list” from Virginia State Police is downloaded onto the computers. The list includes information from all states that report to the Virginia Criminal Information Network.

License plate numbers on the list belong to stolen or carjacked vehicles, stolen license plates and plates associated with crime scenes (such as a kidnapping or robbery where a witness is able to get a plate number). Suffolk Police also can manually add plates associated with wanted or missing people.

The cameras can capture license plates on cars to either side of the police car, whether they are parked or driving.

In the month it’s been in use, the system has helped capture a license plate that had been stolen from a vehicle in Portsmouth.

The system does have a couple weaknesses. The cameras are attracted to the reflection of the license plates, Linville said, which means they occasionally read road signs and other reflective signs. And they cannot distinguish among states, so if it reads a Virginia plate that matches a stolen plate from another state, it will alert on that vehicle.

However, officers double-check before taking any action to ensure they are looking at the vehicle that’s meant to be on the hot list, Linville said.

The system saves plate photos for 15 minutes, which can be helpful in case of a crime like a bank robbery, Linville said. If he has recently been in the general area of the bank robbery and a witness was able to report a make, model or color of the suspect car, he can review the photos of the cars in that area and search for cars that match that description.

The system also saves GPS data for 30 days, so officers know the time, date and exact location they passed a plate.

“Say we had an Amber Alert,” Linville said, referring to a nationwide missing-child alert system. If a license plate belonging to a car reportedly used in the crime shows up on the list of cars passed in the last 30 days, “I kind of know the last time I saw that car,” Linville said. “We’re able to go back to that general area and start our search.”

The new system will be running 16 hours a day from now on, Linville said.